German patent application DE 44 14 547 A1 describes a stationary vehicle air conditioning system in which the vehicle engine mechanically drives a first compressor and a DC electric motor powered by auxiliary vehicle batteries electrically drives a second compressor connected in parallel thereto. In normal operation, i.e., with the engine running, the first compressor circulates the refrigerant in the refrigerant circuit without the assistance of the second compressor, and, in stationary operation, i.e., with the engine off, the second compressor circulates the refrigerant without the assistance of the first compressor. The cooling of the refrigerant in each case takes place in a condenser arranged downstream of the junction of the two branches. This arrangement of components does not permit the systems to operate in an optimal manner.
Other types of stationary air conditioning systems with a cold storage unit are also known in the art, but such cooling systems typically require an undesirable charging time. There is thus a need for a stationary air conditioning system that permits the components to operate in a more optimal manner and without an undesirable charging time.